Does anyone know of a website i can get a diagram of my 03 2500hd's tranny and transfer case, cant figure out where my atf leak is coming from.

I would jb weld it if its a pinhole leak

there is a seal right there you can side it back and put a new seal.

If you are losing fluid and there is no sign of leaks then it can only be going to one of two places. Into the radiator, due to a faulty transmission cooler, or more likely into the transfer case due to a faulty input seal in the transfer case. To confirm if it is going into the radiator just remove the rad cap and look for ATF floating on the coolant. But ONLY DO THIS WHEN THE ENGINE IS COLD!!! You don't want to be sprayed with hot engine coolant. But the safer alternative would be to remove the transfer case fill-plug. If an excessive amount of ATF runs out then the input seal in the transfer case needs replacing.

2.8 litres of dexron II or III ATF. Transfer case takes API GL-5 SAE 75W-90 or 80W-90 gear oil

Are you saying ATF is coming out of filler tube or is it coming out of a vent hole? Could be that cooler failed and its pouring coolant into tranny Possibly,tranny back flow valves are defective and letting ATF drain into pan . Basically take the vehicle to a transmission repair shop.

there are different types of fluids go in that vehicle
the transmission takes ATF
the transfer case for the 4x4 take engine oil ( depend on where you live it take different grades )
the differential takes GL5 also depend on the temperature of your region, it will need different grades.
hope this will explain the confusion

your output seal on the tranny or input seal on your transfer case is bad. you have to pull your transfer case to tell. this is a pretty straight forward job. block wheels. put transfer case in neutral. drop front and rear drive lines.diconnect transfer case shift linkage. there is a short commponent connecting the trans to the transfer case. the bolt on either end face each other. remove the bolts to the transmission. the transfer case is heavier than it looks, i suggest getting help. pull back on the transfer case until it will drop down. it will pull out a bit because of the trans output shaft. replace what will probibly turn out to be the tranny output shaft seal and reassemble in reverse order.

yes you will there is a allen bolt drain plug to drain out the atf. The transfercase takes mopar atf+4.

IF THIS IS A DAILY DRIVER I DONT RECOMMEND IT ,REPLACE THE SEALS, FOR A OFFROAD MUDTRUCK OR HUNTING , I HAVE DONE IT

Transfer cases can be quirky. I've got a 91 Wrangler, an 86 Cherokee and a 75 Blazer. When I go from 2WD to 4WD, they each have their own personality.

There are a number of things I've learned to persuade a stubborn xfer case to shift.

Try mixing these :

• Engine running, vehicle not moving
• Engine off, Shift Xfer case, Restart
  
• Tranny in neutral
  
• Shift Xfer case 'N', Tranny in gear, Tranny in neutral, Xfer case to 4HI or 4LOW (as long as you feel it register), Tranny in gear, try to move
  
• Shift Tranny to Reverse, roll a few yards
• Lock/Unlock the Hubs

To get back to 2WD:

• Drive for a few feet in a straight line
  
• Unlock the hubs
• Tranny Neutral
• Shift xfer case

Let me know how it turns out.
Mike